While at the Viridian booth, I had a chance to take a look at the slide work done by Innovative GunFighter Solutions (IGFS).  IGFS added serrations to the slide of the M&P Shield that Viridian was using to demonstrate the new laser unit for that gun.

The IGFS serrations were very aggressive, but in one direction only.  If you grasped the gun to work the slide, the serrations worked very well to give the hand solid purchase on the slide.  However, the same serrations would not catch on the holster or clothes when being drawn.

IGFS does additional work such as stippling and refinishing.  They can be found at igfs.co.